Let xend choose to do hard or soft domain resumption depending on

whether the domain advertises support for soft resumption in its
elfnotes.

Signed-off-by: Brendan Cully <brendan@kublai.com>

tools/libxc/xc_resume.c

@@ -169,13 +169,9 @@ static int xc_domain_resume_any(int xc_handle, uint32_t domid)
  * (2) should be used only for guests which cannot handle the special
  * new return code. (1) is always safe (but slower).
  */
-int xc_domain_resume(int xc_handle, uint32_t domid)
+int xc_domain_resume(int xc_handle, uint32_t domid, int fast)
 {
-    /*
-     * XXX: Implement a way to select between options (1) and (2).
-     * Or expose the options as two different methods to Python.
-     */
-    return (0
+    return (fast
             ? xc_domain_resume_cooperative(xc_handle, domid)
             : xc_domain_resume_any(xc_handle, domid));
 }

tools/libxc/xenctrl.h

@@ -243,10 +243,12 @@ int xc_domain_destroy(int xc_handle,
  *
  * @parm xc_handle a handle to an open hypervisor interface
  * @parm domid the domain id to resume
+ * @parm fast use cooperative resume (guest must support this)
  * return 0 on success, -1 on failure
  */
 int xc_domain_resume(int xc_handle,
-                      uint32_t domid);
+		     uint32_t domid,
+		     int fast);
 
 /**
  * This function will shutdown a domain. This is intended for use in

tools/python/xen/lowlevel/xc/xc.c

@@ -178,7 +178,17 @@ static PyObject *pyxc_domain_shutdown(XcObject *self, PyObject *args)
 
 static PyObject *pyxc_domain_resume(XcObject *self, PyObject *args)
 {
-    return dom_op(self, args, xc_domain_resume);
+    uint32_t dom;
+    int fast;
+
+    if (!PyArg_ParseTuple(args, "ii", &dom, &fast))
+        return NULL;
+
+    if (xc_domain_resume(self->xc_handle, dom, fast) != 0)
+        return pyxc_error_to_exception();
+
+    Py_INCREF(zero);
+    return zero;
 }
 
 static PyObject *pyxc_vcpu_setaffinity(XcObject *self,
@@ -1124,7 +1134,8 @@ static PyMethodDef pyxc_methods[] = {
       (PyCFunction)pyxc_domain_resume,
       METH_VARARGS, "\n"
       "Resume execution of a suspended domain.\n"
-      " dom [int]: Identifier of domain to be resumed.\n\n"
+      " dom [int]: Identifier of domain to be resumed.\n"
+      " fast [int]: Use cooperative resume.\n\n"
       "Returns: [int] 0 on success; -1 on error.\n" },
 
     { "domain_shutdown", 

tools/python/xen/xend/XendCheckpoint.py

@@ -137,23 +137,6 @@ def save(fd, dominfo, network, live, dst):
         log.exception("Save failed on domain %s (%s).", domain_name,
                       dominfo.getDomid())
 
-        dominfo._releaseDevices()
-        dominfo.testDeviceComplete()
-        dominfo.testvifsComplete()
-        log.debug("XendCheckpoint.save: devices released")
-
-        dominfo._resetChannels()
-
-        dominfo._removeDom('control/shutdown')
-        dominfo._removeDom('device-misc/vif/nextDeviceID')
-
-        dominfo._createChannels()
-        dominfo._introduceDomain()
-        dominfo._storeDomDetails()
-
-        dominfo._createDevices()
-        log.debug("XendCheckpoint.save: devices created")
-
         dominfo.resumeDomain()
         log.debug("XendCheckpoint.save: resumeDomain")
 

tools/python/xen/xend/XendDomainInfo.py

@@ -1662,10 +1662,31 @@ class XendDomainInfo:
     def resumeDomain(self):
         log.debug("XendDomainInfo.resumeDomain(%s)", str(self.domid))
 
+        if self.domid is None:
+            return
         try:
-            if self.domid is not None:
-                xc.domain_resume(self.domid)
-                ResumeDomain(self.domid)
+            # could also fetch a parsed note from xenstore
+            fast = self.info.get_notes().get('SUSPEND_CANCEL') and 1 or 0
+            if not fast:
+                self._releaseDevices()
+                self.testDeviceComplete()
+                self.testvifsComplete()
+                log.debug("XendDomainInfo.resumeDomain: devices released")
+
+                self._resetChannels()
+
+                self._removeDom('control/shutdown')
+                self._removeDom('device-misc/vif/nextDeviceID')
+
+                self._createChannels()
+                self._introduceDomain()
+                self._storeDomDetails()
+
+                self._createDevices()
+                log.debug("XendDomainInfo.resumeDomain: devices created")
+
+            xc.domain_resume(self.domid, fast)
+            ResumeDomain(self.domid)
         except:
             log.exception("XendDomainInfo.resume: xc.domain_resume failed on domain %s." % (str(self.domid)))